


Euphoria

by captain_shitpost



Category: Undertale (Video Game)
Genre: Aftercare, BDSM, Begging, Contest Entry, Ecto-Genitalia (Undertale), Established Relationship, Fontcest, Joint Dislocation, M/M, Masochism, Painplay, Praise Kink, Sadism, Sans Makes Puns, Smut, Swearing
Language: English
Status: Completed
Published: 2017-07-07
Updated: 2017-07-07
Packaged: 2018-11-29 05:08:15
Rating: Explicit
Warnings: Graphic Depictions Of Violence
Chapters: 1
Words: 3,130
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11433789
Author URL: https://archiveofourown.org/users/captain_shitpost/pseuds/captain_shitpost
Summary: Papyrus is a masochist. Sans likes giving him what he needs.





	Euphoria

**Author's Note:**

> Alright this baby is for the [fontcest competition](https://aryisgoingaway.tumblr.com/post/162425028834/fontcest-fanfic-contest) nagisaheichou and aryisgoingaway made. Hope y'all like it!

“alright, if you need me to stop just say the word.”

“Oh my God Sans, we did this before, will you just get on with it?!”

“heh. didn’t realize you wanted a trip to the bone zone so bad, bro.” Sans snickered, shifting his hips a little. It made his cock brush up against his brother’s mound, sending a jolt of pleasure and relief through his bones. Getting his brother worked up and ready sure put him in a _hard_ situation.

Papyrus looked to the ceiling as if searching for the reason for his suffering, giving an amazing view of his long body kneeling above Sans’. He looked somewhere between defeated and annoyed, as he so often did when his brother decided it was time for shitty puns. Which was nearly always.

“Yes brother, I am, in fact, very horny. I am also perfectly capable of locking myself in the bathroom and rubbing one out if you keep this tomfoolery up,” he said in a perfectly even, exasperated voice. Sans laughed harder, making the bed shake.

“alright, alright, i’m just _ribbing_ you, bro,” Sans conceded. “ _come_ on, we can start.”

Papyrus only huffed, ignoring the latest in a line of masterful puns. With an unamused look, he lowered himself enough for his slit to rest on Sans’ cock, then slowly ground down. Both their breaths hitched at the same moment, and while Sans managed to bite it back Papyrus’ trailed off into a soft moan. Just when Sans was starting to relax into the feeling, Papyrus lifted his hips and guided his cock to his entrance before slowly sinking onto it.

Sans inhaled, long and deep, then let out a shuddering sigh. Arguably, his favourite part of sex was this moment, when he first felt that pleasure-relief of Papyrus’ warmth. He opened his sockets and met his brother’s, saw the way his cheekbones were starting to colour and his gaze was just a bit unfocused. He felt the anticipation vibrating softly in his bones, and looking at his brother he knew he felt the same.

He reached out towards his brother’s ribcage, gently rubbing his fingertips up his sternum then down again, stopping at the third rib from the bottom, the first one that wasn’t a floating rib. He wrapped his hands around it firmly, one near the spine and the other close to the sternum, and gave an experimental tug. “alright, you can start moving, bro.”

Papyrus nodded before he lifted his hips up slowly, the well-lubricated motion making Sans’ toes curl, and sank back down. He tugged the rib down harder as he enjoyed the sensation. The pace was infuriatingly slow, but he knew Papyrus needed to pace himself if he wanted to get what he needed. He kept the pressure up on the rib, building the anticipation, increasing the force he was using every time his brother sank down and keeping it steady whenever he rose up again. Papyrus’ blush was starting to creep down his neck, brushing the top of his sternum. When Sans tugged down hard enough for him to flinch, he let out a groan.

“Sans, please,” he murmured, his breathing picking up. Sans chuckled breathlessly.

“well, since you asked so nicely. gonna do it soon, you ready?” he asked, keeping a firm grip on his rib as his brother nodded vigorously.

He took a deep breath, synching with his brother’s. He felt his brother stiffen above him and around his cock. He looked Papyrus straight in the sockets and let up the pressure, grinning as his brother was thrown off-balance for a brief moment. The second he reclaimed his position, he pulled down hard.

The rib came out with a startling pop, the sound almost echoing in the otherwise quiet room for what seemed like an eternity and an instant at the same time. Then suddenly Papyrus registered the pain, his whole body locking in place as he shut his jaw tight and screamed through it.

Sans put the rib to the side carefully so he wouldn’t accidentally break and dust it. Then he rubbed his brother’s femurs slowly, making soothing noises as Papyrus’ screams died down to pants and gasps. “doing great, bro. you’re taking it like a champ.”

Papyrus made a noise between a sob and a bit-off laugh. Every time he inhaled he flinched from the pain, his entire ribcage shaking and flushed from the exertion. Tears were beading in his sockets, but they seemed like they were staying put for now. They wouldn’t for long.

Sans chuckled, enjoying the way Papyrus whined as he wrapped his hand around the matching rib on the other side. He felt something dark and hot and heavy in his ribcage as their bones scraped against each other. “keep moving bro. we’re not done yet.”

Papyrus took a slow breath, keeping them shallow so as to not aggravate his injury, and started moving again. He flinched and tensed up every few moments as the place his rib used to be was stretched or he breathed too deep and fast, but his hips were still moving faster, not smooth and even anymore but jerky, fevered. He moaned as he moved, letting out a sob that seemed almost relieved as his body heated up.

Sans started pulling down on the other rib, putting his weight into it as much as he could. He savored the way Papyrus tensed above and around him, his body radiating heat, the way he whimpered as he tugged harder. “Oh, Sans please, do it, do it,” he moaned, breath shuddering as his motions jostled his ribcage.

Now, Sans had always thought of himself as fragile. All his magic and all his strength faded in the face of the fact that a touch could break him with his meager 1 HP. He had never thought of himself as someone strong. Not until they started doing this. He never even thought of himself as someone that could get off on hurting people before the first time his brother asked him to dislocate his finger.

With a wide grin, strained from the heat and excitement lying heavy in his bones, he pulled hard until he felt a pop underneath his palms.

Papyrus screamed for real now, punching the mattress to the side of Sans’ head to let out the wound up energy of the pain in his ribcage. He clenched his jaw shut, hissing out his breath slowly, sobbing as tears finally began to roll down his face, leaving tracks down the perfect bones of his cheekbones and pooling underneath his mandible, dripping onto Sans like warm rain. Sans watched him shut his eyes, forcing his breath to even out, making his body stop fighting the pain and leaning into it instead, slipping into that place of strange peace Sans could never follow him to but was always happy to guide him there.

If someone made Sans take half of what Papyrus could, he would break down. He’d pray for the pain to stop, he’d maybe even fight back to escape the torment. Papyrus wasn’t like that. Where others ran from pain, he embraced it. Where Sans let his hurt consume him, Papyrus made it a part of himself, one he could control instead of letting it control him.

He felt his cock twitch. His brother really was breathtaking.

Papyrus didn’t need prompting to move on his own this time. “fuck yeah, just like that bro, just keep going,” Sans panted out, one hand stroking his brother’s spine with a strong grip as he slid up and down his length, the other trailing over his ribs, always stopping just above the empty spaces. Papyrus’ sobs were mixed with absolutely filthy moans, stretching his spine on purpose just enough to make his breath catch in pain every few thrusts.

His brother gripped the bedsheets harder, getting a tighter grip so he could move better. Sans couldn’t blame him, his own cock felt like it was crying for relief. He trailed both hands to the flushed and irritated joints where the ribs used to be, then dug his fingertips in the maltreated areas. Papyrus wheezed, trying to breathe through the pain, his harsh pants taking the shape of his name, formed but not given a voice.

Sans wrapped his hand around his sternum, digging his phalanges into the joints and gripping hard. Papyrus jolted, his whole body tensing as a new wave of pain flowed through him. His gaze was fuzzy, lost in the onslaught of sensation. Sans wasn’t sure if his brother was capable of thinking right now or if he could only passively feel, endure the pain contrasting the pleasure, fixate on the pleasure honing the edge of pain.

Papyrus shifted his weight to his left hand, his pace slowing down from the loss of balance. He held out his shaky arm reverently, like he was offering a gift to a god.

“Sans please, I-mh-I’m so close,” he begged, looking at him with the kind of absolute trust a child would have before they realized that there were truly bad things in the world. It terrified and thrilled Sans in equal measure, being trusted like that. Papyrus didn’t always trust him to take care of himself, but he trusted him with his own body, his own life, without a trace of doubt. He dug his fingers in the joints again before slowly letting go.

“give-give me your other hand,” he groaned out. He knew he didn’t want Papyrus’ dominant hand to hurt tomorrow, but it was difficult, not losing himself in the moment. He was so damn close it physically hurt him, and he thought distantly that, for a second, Papyrus somehow shared with him a fraction of his pain.

Papyrus somehow managed to change hands while still slowly rocking above him. Sans took his left hand in his own, using the other to grip his little finger. He applied pressure to it, watching Papyrus tense up again, face expectant. Sans rocked his hips a bit to get him moving again, Papyrus having a hard time moving while trying to balance on only one arm. He couldn’t go fast, not with his missing ribs, so instead he rocked hard, the pain the motion caused making his body shudder in waves as he alternated strong thrusts with slow circles, trying to take as much of his brother’s cock as he possibly could.

Sans bit back a moan, tipping the finger back until Papyrus hissed. Papyrus was panting, sobbing and whining at the now violent pace he set, obviously needing just a little bit more to tip over. Sans took as deep a breath as he could, then pulled the finger backwards, feeling a pop. Papyrus froze in place for a moment, not a bone moving, not taking a breath, the only part of his body still mobile being the tears rolling down his cheeks. Then with a choking sound he rose up and slammed his hips down, letting out a cry of ecstasy. Sans could only call his name like a chant as his brother rode out his orgasm, felling the slickness of his brother’s walls increase as they twitched around his cock and the warm, gentle glow of his magic caressed his chest.

He threaded their fingers together, careful around the dislocated digit, as Papyrus’s body still convulsed from the aftershocks. He squeezed his hand firmly, latching onto the comfort they both needed. Slowly, his brother slowed down the violent thrusts, coming off his high just as Sans was so close to the edge he could taste it. Sans dug his phalanges into his hips.

“fuck, bro, please, just a little more,” he whimpered, not able to suppress a moan as Papyrus kept rocking into him slowly, squeezing his hand back. He tried to keep his sockets open, drink in the sight of his brother completely fucked out, something in the way he seemed to be on autopilot making pride and arousal burn inside of him. He gave him that. He could give his brother this and no one else could, he could dislocate every bone in his body and he’d still look at him with that pure trust and adoration in his eyes. His brother would give him the gift of himself and then be happy to be broken, and as much as Sans broke him, it would never be in a way that couldn’t be fixed.

“stars, you’re amazing bro, you’re so fucking perfect, oh _fuck_ -” Sans groaned, thrusting up as his cock pulsed, filling his brother with magic. He felt tingles all the way to his toes, and they just kept _going_. It felt like he was floating in that white space of pleasure for years, just him and his brother, connected in every single way.

After a small eternity, he felt the feeling start subsiding, leaving behind a deep exhausted contentment thrumming in his bones. He cracked open his sockets again to see his brother looking at him, tired and out of it and smiling in satisfaction. Sans felt his grin widen in response.

With a breathless laugh, Sans let his magic start to dissipate, leaving just the slightly empty feeling of bone. Papyrus’ sockets started closing and he swayed in place suddenly, Sans propping himself up just fast enough to hold him up before he collapsed.

“woah, you, hah, you really crash hard,” Sans said with a laugh, trying to catch his breath, feeling Papyrus mumble something above him. With a happy grin, he guided his brother towards the bed, pausing and readjusting every time he winced or hissed as his ribs were jolted. He may have done this before, both after sex and on the very rare occasions his brother crashed somewhere outside of his room, but it still took a while to move Papyrus when he wasn’t awake enough to move himself. He was nearly 2 heads taller than Sans after all. His baby brother, the walking lamp post.

With lots of maneuvering and cajoling, Sans managed to prop him up on a pillow, Papyrus making a token effort to move himself but just aggravating his wounds more. Sans took the ribs he put on the side, trying to figure out for a moment which one was left and which one was right, before leaning over to grab some gauze. “gonna pop your ribs back in, papyrus. it’ll only take a minute, okay?”

Papyrus nodded weakly, still off somewhere in that quiet place in his head. Sans put the first rib in place. “alright, three, two, one-” he said before carefully yet decisively popping it back in place. Papyrus screamed through clenched teeth, balling up the sheets in his right hand. Sans slowly wound gauze to keep the bone in place for now, then quickly popped the other rib in before Papyrus could register it. Lastly, he took Papyrus’ hand in his own, popping the phalanx back in place as Papyrus started crying again. He made soothing noises at him, peppering him with praise as he rubbed gentle circles into his hand.

Next he had to get up, and only the thought of his brother needing him was enough to motivate him to do so after than mind-bending orgasm. He walked over to the table where he left some oatmeal and milk, carrying it back to the bed. Papyrus was apparently slowly coming back from his daze since he made eye contact with Sans after he sat down on the bed and stirred. Sans grinned, scooping up the now cold food and nudging his teeth with a spoon. “come on bro, you gotta eat. you want me to make car noises? vroom vroom, here comes the car, it’s a convertebrae!” Sans tittered. Papyrus gave him an agonized look, caught somewhere between incredulity and fond disgust. He swallowed once before opening his mouth to say something, and Sans chose that moment to shove a spoonful into his mouth. Papyrus sputtered in protest at first, but apparently decided it wasn’t worth the effort and let himself be fed.

He ate a few more spoons before Sans gave him the milk, at first gingerly taking a sip before grabbing the glass along with Sans’ hand to chug the contents down. When Sans took the glass away and approached with the oatmeal again, Papyrus groaned. “I can’t eat all of that Sans, I’m not a trash can,” he scoffed, voice cracking from its previous abuse.

“bro, you need to eat it so you can heal right. i don’t want your rib to dislocate after undyne gives you one of her _friendly pats_ ,” Sans explained, putting on his trademarked Pestering Parent look. Papyrus seemed annoyed for a moment, before looking to the side with a hint of a blush climbing on his cheeks, a gesture Sans had seen him make since he was a child. Shyness.

“…I want it to hurt tomorrow too,” he said, voice quiet for his standards. Sans sighed, then put his palm to Papyrus’ face to tilt it back to him, making eye contact. He always felt a bit like he failed when Papyrus felt self-conscious. Like he didn’t manage to convince him that he’d never think less of him, no matter what he needed.

“i get it, bro. but i can’t risk you actually hurting yourself because we didn’t take care. it’s part of the deal, bro. we do this together, you get your pain, i get you being absolutely sexy and i take care of you so you don’t get hurt for real,” he murmured, rubbing his cheekbone with his thumb. It was still a bit wet from his tears. “but don’t worry, you’ll be sore tomorrow no matter what i do.”

Papyrus smiled, tired but as beaming as it would be when he looked at his brother at times when no puns were uttered. Thankfully, this time he didn’t complain as he ate half the bowl before claiming he was done.

After putting away the dishes and turning off the lights, Sans got under the blankets and snuggled up to his brother, close enough to touch but not enough to put pressure on his ribs. Papyrus’ face was indistinct in the darkness, but Sans could feel his warmth as he stretched carefully to clank their teeth together. He could just barely see his sockets, looking straight into his. Every breath Papyrus exhaled, he inhaled. As it should be.

Just when he was drifting off, he felt Papyrus’ hand touch his. Gently, he intertwined their fingers, keeping them close even in their sleep. “good night, papyrus.”

He felt the shudder of the bed as Papyrus laughed with the quietest “nyeh-heh”. “Good night, brother. And Sans?”

“yeah, bro?”

“Thank you.”

Sans laughed sleepily. “It was my pleasure.”

**Author's Note:**

> And the next morning Papyrus throws a fit because they're both covered in dry, crusty magic and the sheets can't be salvaged
> 
> You know how hard it is to find decent BDSM fanfics? Most are either light BDSM, miss the point of BDSM entirely or are non-con. Can't I just have some consensual bone-breaking, crackalacking sex?
> 
> Also, [this is the music I wrote this fic to](https://www.youtube.com/watch?v=llyiQ4I-mcQ&list=PL-l7Wl60y-JTx19dAdn6lukJrjbd2wtuE&index=109).


End file.
